Answer:
1. They needed to develop multiple components in software programs.
2. The ability to overlap the development to be more evolutionary in nature.
3. The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.
Explanation:
Software development life cycle (SDLC) can be defined as a strategic process or methodology that defines the key steps or stages for creating and implementing high quality software applications.
In SDLC, a waterfall model can be defined as a process which involves sequentially breaking the software development into linear phases. Thus, the development phase takes a downward flow like a waterfall and as such each phase must be completed before starting another without any overlap in the process.
An incremental model refers to the process in which the requirements or criteria of the software development is divided into many standalone modules until the program is completed.
Also, a spiral model can be defined as an evolutionary SDLC that is risk-driven in nature and typically comprises of both an iterative and a waterfall model. Spiral model of SDLC consist of these phases; planning, risk analysis, engineering and evaluation.
What motivated software engineers to move from the waterfall model to the incremental or spiral model is actually due to the following fact;
They needed to develop multiple components in software programs. The ability to overlap the development to be more evolutionary in nature. The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.An engineer is trying to build a new measurement tool. Which step should the engineer complete first? A. Design a model of the tool to be tested. B. Precisely define the problem that is to be solved. Selected:c. Write a list of the criteria and constraints for the tool.This answer is incorrect. D. Conduct research on how similar problems were solved in the past.
Answer:
B. Precisely define the problem that is to be solved.
Explanation:
Engineering can be defined as the scientific and technological principles that is used for the design, development, operation and control of tools, machines or equipments, structures and systems. These machines, tools, systems and structures are typically designed and developed for the purpose of solving peculiar problems relating to human life. Simply stated, engineering is focused on proffering solutions to real life problems through a design process.
Generally, the design process comprises of series of steps used for the development of various tools, machines, structures and systems. In a chronological order, the basic steps of a design process are;
1. Define the problem: to proffer a solution to any problem, you have to precisely define the problem that is to be solved. Therefore, this is the first step of the design process.
2. Conduct a research: the engineer should collect or gather data (informations) relating to the project.
3. Brainstorming and analysis of data: this is the stage where the engineer conceptualize his or her ideas.
4. Create a prototype or simulated model of the product.
5. Product analytics and test: this is where the product is being used and tested for any flaw, error or defects. Thus, troubleshooting is also required at this stage.
Hence, if an engineer is trying to build a new measurement tool; the first step the engineer should complete is to precisely define the problem that is to be solved so as to have a good clear-cut understanding of the problem.
Read the following paragraph as quickly as you can, and see if you encounter any diculties.
Aoccdrnig to rscheearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by itslef but the wrod as a wlohe.
This has been presented as an example of a principle of human reading compre-hension. If you keep the rst letter and the last letter of a word in their correct positions, then scramble the letters in between, the word is still quite readable in the context of an accompanying paragraph. However, it seems that this is a bit of a myth and not truly based on solid research.1 In short, for longer words the task is much more dicult. Nonetheless, we are going to imitate the process on some English text.
The task will be to read in a paragraph from a le, scramble the internal letters of each word, and then write the result to a le. Handling punctuation is tricky. You are required to deal with punctuation that comes at the end of a word (period, question mark, exclamation, etc.)|that is, punctuation is left untouched and does not count as the nal unscrambled letter. Optionally, one can deal with the more dicult task of handling all punctuation, such as apostrophes for possessives or hyphenated words. Truly randomizing the order of letters is a task for later in the text, but we can do some reasonable approximations now. Attacking this problem in a divide-and-conquer way should begin by writing code to scramble the letters in a word.
Create a dierent solution by dening scrambling functions for each of the following approaches: (Each approach counts as a dierent problem)
(a) For each letter choose a random number and rotate that letter by the random amount. Import random and use the random.randint(a,b) function where `a' and `b' dene the range of random numbers returned.
(b) Implement a dierent method to scrambling the letters. You must clearly describe in the comments the process to scramble the letters in place.It must be dierent than the process from part a.
Answer:
a
Explanation:
just took the quiz
Don't break or crush mercury-containing lamps because mercury powder may be released.
A) TrueB) False
Which of the following tasks might a civil engineer perform during a project’s construction phase in a design-build approach? (Select all that apply.)
Work with construction management to solve specific problems as they arise.
Draw up the contracts for construction management.
Ensure compliance with safety standards.
Provide information on design changes.
Answer:
Draw up the contract for construction management.
Answer:
Work with construction management to solve specific problems as they arise.
Ensure compliance with safety standards.
Explanation:
Which color of white light bends the most when it is refracted by a prism? red green yellow orange
The color of white light bends the most when it is refracted by a prism is green after the violet.
Why green bents towards the light?The shorter the wavelength of the mild, the greater its miles refracted. As a result, crimson mild is refracted the least, and violet mild is refracted the most - inflicting the colored mild to unfold out to shape a spectrum.
The hues of white mild withinside the order of lowering wavelength are crimson orange-yellow inexperienced blue indigo violet. Fro the listing we are given withinside the alternatives inexperienced has the shortest wavelength than others. Therefore inexperienced will bend the most.
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What are the two most important things to remember when at the end of your interview?
1. When the interviewer asked if you have any questions at the end of the interview don't say no. You should always say yes your interviewer is expecting you to ask a few good questions before ending the interview.
2. Always thank the interviewer for their time and effort to interview you. This would look very good for you and its a nice way to help wrap up the interview.
The point at 0°, 0° is
Common car loan duration
Answer:
In 2019, the average term length was 69 months for new cars and 65 months for used vehicles. Most car loans are available in 12 month increments, lasting between two and eight years. The most common loan terms are 24, 36, 48, 60, 72, and 84 months, according to Autotrader
Explanation:
Timken rates its bearings for 3000 hours at 500 rev/min. Determine the catalog rating for a ball bearing running for 10000 hours at 1800 rev/min with a load of 2.75 kN with a reliability of 90 percent.
Answer:
C₁₀ = 6.3 KN
Explanation:
The catalog rating of a bearing can be found by using the following formula:
C₁₀ = F [Ln/L₀n₀]^1/3
where,
C₁₀ = Catalog Rating = ?
F = Design Load = 2.75 KN
L = Design Life = 1800 rev/min
n = No. of Hours Desired = 10000 h
L₀ = Rating Life = 500 rev/min
n₀ = No. of Hours Rated = 3000 h
Therefore,
C₁₀ = [2.75 KN][(1800 rev/min)(10000 h)/(500 rev/min)(3000 h)]^1/3
C₁₀ = (2.75 KN)(2.289)
C₁₀ = 6.3 KN
Help!!
Which of the following describes the first and foremost guideline in dimensioning?
A. Legibility
B. Measurement
C. Accuracy
D. Sketching
Answer:
it should be accuracy
Explanation:
Answer:
option C
Explanation:
Match each titration term with its definition.
Process of slowly adding a solution to react with another solution and determine the Choose... concentration of one of the solutions tased on the reaction between them
Solution of an unknown concentration that has another solution slowly added to it Choose...
When the required amount of one solution has been added to the second solution to Choose... complete the reaction
Solution of known concentration that is slowly added to a solution of unknown Choose... concentration
Glassware that allows a solution to be precisely and slowly added to another solution Choose...
A reagent added to the analyte solution that changes color when the reaction is Choose... complete
Answer:
1) titration
2) titrand
3) equivalence point
4) titrant
5) Burette
6) Indicator
Explanation:
The process in which a known volume of a standard solution is added to another solution so that the standard solution can react with the solution of unknown concentration such that its concentration is determined can be referred to as titration.
The solution which is added to another solution is called the titrant. The titrand is the solution of unknown concentration
A burette is a glassware used to slowly add a known volume of the titrant to the titrand.
The indicator used signals the point when the reaction is complete by a color change. At this point, a stoichiometric amount of titrant has been added to the titrand. This is also referred to as the equivalence point.
Which type of design does not need special care for the placement of dimensions?
Answer:
cubes
Explanation:
Design for software engineering does not need special care for the placement of dimensions. Software engineering generally deals with arranging lines of coding.
What is Software Engineering Design?In order to achieve a software's goal by using lower-level, machine-understandable algorithms and a set of parameters based on project requirements or environmental constraints, software design is the process of outlining solutions, planning, and specifying a method of implementation based on the needs of the user.
Software engineering is the application of engineering principles, which are often employed in the design, development, testing, deployment, and management of physical systems to the design.
Therefore, the main focus of software engineering is organizing coded lines that are kept in a device's or computer's memory rather than in actual physical space.
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Why do the changes to the mass of the planet NOT AFFECT the orbital path of the Planet?
Answer:
changes of Mass affect the planet because... I'm sorry If this didn't help.
What problem solving strategies don’t gaurentee solutions but make efficient use of time
A spherical ball has 3cm internal diameter and its inner surface temperature is 250˚C and the outer surface temperature is 30˚C. Calculate the outer diameter of the ball if the heat loss from the ball is 1600W and has 2.75W/m.˚C thermal conductivity.
Answer:
The outer diameter of the ball is 6.2138 cm
Explanation:
The formula to apply is ;
Heat loss ,
[tex]Q/t=kA*\frac{( T_1-T_2)}{d}[/tex]
where ;
Q/t=total heat loss from the ball = 1600 w
k=coefficient of heat transmission through the ball= 2.75 W/m.˚C
A=area in m² of the ball with the coefficient of heat transmission
T₁=Hot temperature
T₂=Cold temperatures
d=thickness of the ball
Area of spherical ball using internal diameter, 3cm= 0.03 m will be
Radius = half the diameter = 0.03/2 = 0.015
Area = 4 *π*r²
Area = 4*π*0.015² = 0.002827 m²
Apply the formula for heat loss to get the thickness as:
1600 = {2.75 * 0.002827 *(250-30 ) }/d
1600 =1.711/d
1600d = 1.711
d=1.711/1600 = 0.001069 m
d= 0.1069
Using internal radius and the thickness to get outer radius as;
3 + 0.1069 = 3.1069 cm
Outer diameter will be twice the outer radius
2*3.1069 = 6.2138 cm
Under a subsection for geological hazards the buyer is encouraged to obtain an read the booklet
Answer:
Buyer is encouraged to obtain and read the booklet entitled "The Homeowners Guide to Earthquake Safety." In most cases a questionnaire within the booklet must be completed by Seller and the entire booklet given to the Buyer if the Property was built prior to 1960.
What are the differences between separately and shunt DC motor?
calculate the magnitude of the force acting on the pin at D. Pin C is fixed in DE and bears against the smooth slot in the triangular plate.
Answer:
hello your question lacks the required diagram attached below is the diagram
answer : 58.47 N
Explanation:
The magnitude of the force acting on the Pin D
Fd = [tex]\sqrt{Dx^2 + Dy^2}[/tex]
= [tex]\sqrt{16.80^2 + 56^2}[/tex]
= 58.465 N
Dx = 16.80 N
Dy = 56 N
hello attached below is the detailed solution
Which of the following is considered a bated standard
Answer:
is it multiple choice or....
The insulator is the connection between the grounded circuit conductor and the equipment grounding conductor at the service.
Using a roof calculator or rafter length guidebook, calculate the theoretical length of the common rafters for a gable roof on a building which is 12’ wide by 36’ long, with a slope of 5/12.
Answer:
35 feet
Explanation:
Explain why the scenario below fails to illustrate an understanding of the importance of metrology. Situation: Natalie is a calibration technician at a food production plant. Natalie: "The oven is just a couple of degrees off. I will just wait a few hours to see if it will level out on its own"
Answer:
Explanation:
The situation being described completely fails in regard to the importance of metrology. This is because the main importance of metrology is making sure that all of the measurements in a process are as accurate as possible. This accuracy allows an entire process to function efficiently and without errors. In a food production plant, each individual department of the plant relies on the previous function to have completed their job with the correct and accurate instructions so that they can fulfill their functions correctly and end up with a perfect product. If the oven (like in this scenario) is a couple of degrees off it can cause the product to come out burned or undercooked, which will then get transferred to the next part of production which will also fail due to the failed input (burned or undercooked product). This will ultimately lead to an unusable product at the end of the process and money wasted. Which in a large production plant means thousands of products in a single batch are thrown away.
In terms of the necessity of metrology, the situation stated absolutely fails. This is because metrology's primary goal is to ensure that all measurements in a process are as precise as feasible. This precision allows a whole process to run smoothly and error-free. If the oven temperature is wrong by a few degrees, the product will come out charred or undercooked, and the product will be sent to the next step of the process, which will also fail owing to the failed input. This will result in a useless product and a waste of money at the end of the procedure. In a big manufacturing facility, this means thousands of goods are discarded in a single batch.
6. You are an electrician working in an industrial plant. You are building a motor control cabinet that contains six motor starters and six pilot lamps. All control components operate on 120 volts AC. Two of the motor starters have coil currents of 0.1 amperes each and four have coil currents of 0.18 amperes each. The six pilot lamps are rated at 5 watts each. The supply room has control transformers with the following rating (in volt-amperes):
75, 100, 150, 250, 300, and 500.
Which of the available control transformers should you choose to supply the power for all the control components in the cabinet?
Answer:
It's indeed safer to suggest a 150 VA transformer. Following table however is the clarification given.
Explanation:
For 2 motors with 0.1 A, the Power will be:
P = [tex]2\times 120\times 0.1[/tex]
= [tex]24 \ W[/tex]
For 4 motors with 0.18 A, the Power will be:
P = [tex]4\times 120\times 0.18[/tex]
= [tex]86.4 \ W[/tex]
As we know, for 6 pilot lamps, the power is "5 W".
So,
The total power will be:
⇒ P = [tex]24+86.4+5[/tex]
= [tex]115.4 \ W[/tex]
Now,
Consider the power factor to be "0.95"
VA of transformer is:
= [tex]PF\times Power[/tex]
= [tex]115.4\times 0.9[/tex]
= [tex]109.63 \ VA[/tex]
Tech A says that most electric fuel pumps are now mounted inside of the fuel tank. Tech B says that fuel flows through the center of the electric pump and is used to cool the pump. Who is correct?
Answer:
both
Explanation:
Tech A says that most electric fuel pumps are now mounted inside of the fuel tank. Tech B says that fuel flows through the center of the electric pump and is used to cool the pump. Who is correct? quizlet said so
In this case, both Technicians are right.
The electric fuel pump is a device that powers a vehicle's engine system by providing fuel.There are two classes of electric fuel pumps: external fuel pumps and in-tank fuel pumps.In modern vehicles (also in motorcycles) the electric fuel pump is now located inside the fuel tank.In conclusion, both Technicians are right.
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5-81 The shaft is made of A-36 steel and is fixed at end D, while end A is allowed to rotate 0.005 rad when the torque is applied. Determine the torsional reactions at these supports.
Answer:
The answer is "7.73 kip-ft".
Explanation:
Using this equation, calculate the polar moment of shaft inertia:
[tex]J= \frac{\pi }{32} d^4\\\\[/tex]
[tex]= \frac{\pi}{ 32} \times 6^4\\\\= 127.234 \ \ in^4[/tex]
Equate the number of moments in x:
[tex]\sum M_x =0[/tex]
[tex]\to T_A-T_B +T_C+T_D =0\\\\\to T_A-40 +20+T_D =0[/tex]
Calculate the torsional response at A using the superposition method:
[tex]\to \phi_A =(\phi_A)_{T} - (\phi_A)_{T_A}\\\\[/tex]
[tex]= \frac{T_B L_{BC}}{JG}+ \frac{T_C L_{CD}}{JG} - \frac{T_A L_{AD}}{JG}\\\\[/tex]
[tex]0.05= \frac{40 \times 12 \times 2 \times 12}{127.234 \times 11 \times 10^3}+ \frac{20 \times 12 \times 1.5 \times 12 }{127.234 \times 11 \times 10^3} - \frac{T_A \times 12 \times 5 \times 12}{127.234 \times 11 \times 10^3}[/tex]
[tex]0.05= (8.22 \times 10^{-3})+ (3.086 \times 10^{-3})- (5.14 \times 10^{-4} \ T_A)\\\\[/tex]
[tex]\to T_A =12.27 kip \ ft \\\\[/tex]
The torsional answer in help A is 12.27 kip- ft. It replace the necessary equation values:
[tex]\to T_A-40 +20+T_D =0 \\\\\to 12.27-40+20+T_D=0\\\\T_D=7.73 kip \ ft[/tex]
The torsional reactions at the given supports are;
T_a = 12.3 Kip.ft and T_d = 7.7 Kip.ft
What are Torsional Reactions from Torque?From the image of the shaft attached, if we take a free body diagram and torsion about x, we will have;
∑Mₓ = 0;
T_a + T_d + 20 - 40 = 0 -----(1)
Using the method of superposition, we have;
Φ_a = (Φ_a)_T - (Φ_a)_T_a
Formula for rotation Φ is;
Φ = TL/(JG)
Thus;
0.005 = [tex][\frac{40 * 12 * 2 * 12}{(\pi/2) *3^{4} * 11 * 10^{3}} + \frac{20 * 12 * 1.5 * 12}{(\pi/2) *3^{4} * 11 * 10^{3}}] - \frac{T_{A} * 12 * 5 * 12}{(\pi/2) *3^{4} * 11 * 10^{3}}[/tex]
Solving for T_a in this gives;
T_a = 12.3 Kip.ft
Thus, from eq 1;
12.3 + T_d + 20 - 40 = 0
T_d = 20 - 12.3
T_d = 7.7 Kip.ft
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.
Describe a ways car manufacturers try to reduce drag and why.
Answer:
Aerodynamic drag can be reduced by altering the density of the air and the vehicle speed, but these factors are not easily controlled. Instead, to reduce drag, car manufacturers can make the height and width of the front of the car smaller. ... This shape reduces drag and the forces that try to propel the car backwards.
Answer:
Car manufacturers can make the height and width of the front of the car smaller.
Explanation:
The shape reduces drag and the forces it to propel the car backwards.
A steam pipe passes through a chemical plant, where wind passes in cross-flow over the outside of the pipe. The steam is saturated at 17.90 bar and you can assume that the resistances to heat transfer inside the pipe and of the pipe itself are minimal, so that the outside surface temperature of the pipe is equal to the saturation temperature of the steam. The pipe is stainless steel and has an outside diameter of 6.75 cm and a length of 34.7 m. The air flows over the pipe at 7.6 m/s and has a bulk fluid temperature of 27 °C.
A. What is the rate of heat transfer from the pipe to the air?
B. would your answer change if the air flow direction changes to parallel flow? If so, calculate that q as well.
Answer:
a) the rate of heat transfer from the pipe to the air is 23.866 watts
b) YES, the rate of heat transfer changes to 3518.61 watt
Explanation:
Given that:
steam is saturated at 17.90 bar.
the pipe is stainless steel and has an outside diameter of 6.75 cm
length = 34.7 m
Air flows over the pipe at 7.6 m/s
Bulk fluid temperature of 27°C
we know that
hD/k = 0.028 (Re)^0.8 (Pr)^0.33
Outside diameter of pipe = 6.75 cm
length of the pipe = 34.7 m
velocity of air = 7.6 m/s
Cp of air = 1.005 kJ/Kgk
viscosity of air = 1.81 × 10⁻⁵ kg/(m.sec)
thermal conductivity of air = 2.624 × 10⁻⁵ kw/m.k
so as
hD/k = 0.028 (Re)^0.8 (Pr)^0.33
hD/k = 0.028 (Dvp / u)^0.8 (Cpu / k)^0.33
(h × 0.0675 / 2.624 × 10⁻⁵) = (0.028 ([0.0675 × 7.6 × 1.225] / [1.81 ×10⁻⁵])^0.8) (((1.005 × 1.81 × 10⁻⁵) / (2.624 × 10⁻⁵))^0.33))
h = 0.0414 w/m².k
a)
Now to find the rate of heat transfer Q
Q = hAΔT
Q = 0.0414 × (2π × 0.03375 × 34.7) × (105.383 - 27)
Q = 23.866 watts
therefore the rate of heat transfer from the pipe to the air is 23.866 watts
b)
Now the flow direction changes to parallel flow, then
(h × 0.0675 / 2.624 × 10⁻⁵) = (0.028 ([34.7 × 7.6 × 1.225] / [1.81 ×10⁻⁵])^0.8) (((1.005 × 1.81 × 10⁻⁵) / (2.624 × 10⁻⁵))^0.33))
h = 6.1036 w/m².k
so from the steam table, saturated steam at 17.70 bar, temperature of steam will be 105.383°C
so to find the rate of heat transfer Q
Q = hAΔT
Q = 6.1036 × (2π × 0.03375 × 34.7) × (105.383 - 27)
Q = 3518.61 watt
Therefore the rate of heat transfer changes to 3518.61 watt
Assume you have a steel beam that is 20 feet long and carries a concentrated load of 500 pounds at a distance of 15 feet from Reaction (R ). Reaction (R ) is pinned 5 feet from the load. What are the values in lbs for R and R ? A. 475 and 25 B. 500 and 00 C. 375 and 125 D. 125 and 375
Answer:
The answer is "Option D".
Explanation:
[tex]\to \epsilon_T= 0\\\\\to R+R_1=500 \ lb \\\\\to \epsilon \ M_{pin} > 0\\\\\to -R \times 20 +(500 \times 5) =0\\\\\to 2500 =20R\\\\\to 20R= 2500\\\\\to R= \frac{2500}{20}\\\\\to R= \frac{250}{2}\\\\\to R= 125 \ lb \\\\\to R_1 =500-125\\[/tex]
[tex]=375 \ lb \\[/tex]
Seth wants to build a wall of bricks. Which equipment will help him in the process?
OA masonry pump
OB. hacksaw
OC. mortar mixer
OD. pressurized cleaning equipment
Answer:
it's B I think
Explanation:
hopefully that helps you
Answer: C
Explanation: A mortar mixer is the equipment that would help Seth in the process of building a wall of bricks. A mortar mixer is used to mix the mortar, which is the binding material used to hold the bricks together. It ensures the mortar is properly mixed to the right consistency for laying the bricks.
Suppose an underground storage tank has been leaking for many years, contaminating a groundwater and causing a contaminant concentration directly beneath the site of 0.30 mg/L. The contamination is flowing at the rate of 0.5 ft/day toward a public drinking water well 1 mile away. The contaminant degrades with a rate constant of 1.94 x 10^-4 1/day. Draw a picture of the system. Estimate the steady-state pollutant concentration expected at the well. If the slope factor is 0.02 (mg/kg-day)^-1.
Required:
Estimate the cancer risk for an adult male drinking the water for 10 years.
Answer: the cancer risk for an adult male drinking the water for 10 years is 2.88 × 10⁻⁶
Explanation:
firstly, we find the time t required to travel for the contaminant to the well;
Given that, contamination flowing rate = 0.5 ft/day
Distance of well from the site = 1 mile = 5280 ft
so t = 5280 / 0.5 = 10560 days
k is given as 1.94 x 10⁻⁴ 1/day
next we find the Pollutant concentration Ct in the well
Ct = C₀ × e^-( 1.94 x 10⁻⁴ × 10560)
Ct = 0.3 x e^-(kt)
Ct= 0.0386 mg/L
next we determine the chronic daily intake, CDI
CDI = (C x CR x EF x ED) / (BW x AT)
where C is average concentration of the contaminant(0.0368mg/L), CR is contact rate (2L/day), EF is exposure frequency (350days/Year), ED is exposure duration (10 years), BW is average body weight (70kg).
now we substitute
CDI = (0.0368 x 2 x 350 x 10) / ((70x 365) x 70)
= 257.7 / 1788500
= 0.000144 mg/Kg.day
CDI = 1.44 x 10⁻⁴ mg/kg.day
Finally we calculate the cancer risk, R
Slope factor SF is given as 0.02 Kg.day/mg
Risk, R = I x SF
= 1.44 x 10⁻⁴ mg/kg.day x 0.02Kg.day/mg
R = 2.88 × 10⁻⁶
therefore the cancer risk for an adult male drinking the water for 10 years is 2.88 × 10⁻⁶